1. Field of the Invention
This invention relates to a control device for a hybrid vehicle, the hybrid vehicle provided with the same, and a control method for the hybrid vehicle, and particularly to a control device for a hybrid vehicle including an internal combustion engine and a drive motor, the hybrid vehicle provided with the same, and a control method for the hybrid vehicle.
2. Description of Related Art
Japanese Patent Application Publication No. 2003-328804 (JP 2003-328804 A) discloses a hybrid vehicle including an internal combustion engine, a drive motor, a generator motor, and a power split device. In the hybrid vehicle, an output from the internal combustion engine is divided by the power split device into a power for generating electricity and a power for driving. The generator motor generates electricity using the power for generating electricity resulting from the division by the power split device (see JP 2003-328804 A).
In such a hybrid vehicle as described above, even when the drive motor fails, limp-home driving can be performed by driving the internal combustion engine. At this time, when an amount of electricity stored in an electricity storage device that stores the electric power for driving decreases, the amount of electricity generated by the generator motor is increased to charge the electricity storage device. Since an output power from the internal combustion engine is increased to increase the amount of electricity generated by the generator motor, the rotation speed of the internal combustion engine increases. In such a case, when the driving force required for the hybrid vehicle decreases, if the rotation speed of the internal combustion engine increases to charge the electricity storage device, drivability deteriorates.